Named for the German word for clotting—"koagulation"—vitamin K is responsible for enabling your blood to clot, ensuring you don't bleed out from a paper cut or cat scratch.
Vitamin K also teams up with vitamin D and calcium to strengthen your bones. Because vitamin K is fat soluble, be sure to consume this nutrient at the same time as a (healthy) fat. This will aid with its absorption.
How much you should have: Aim for 90 to 120 micrograms daily—that means a cup of spinach or a small amount of kale. If you're not getting enough vitamin K from food, try taking a 100 mcg supplement daily.